diff options
Diffstat (limited to 'net/ipv6/ndisc.c')
| -rw-r--r-- | net/ipv6/ndisc.c | 1892 |
1 files changed, 1892 insertions, 0 deletions
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c new file mode 100644 index 00000000..176b4693 --- /dev/null +++ b/net/ipv6/ndisc.c @@ -0,0 +1,1892 @@ +/* + * Neighbour Discovery for IPv6 + * Linux INET6 implementation + * + * Authors: + * Pedro Roque <roque@di.fc.ul.pt> + * Mike Shaver <shaver@ingenia.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +/* + * Changes: + * + * Pierre Ynard : export userland ND options + * through netlink (RDNSS support) + * Lars Fenneberg : fixed MTU setting on receipt + * of an RA. + * Janos Farkas : kmalloc failure checks + * Alexey Kuznetsov : state machine reworked + * and moved to net/core. + * Pekka Savola : RFC2461 validation + * YOSHIFUJI Hideaki @USAGI : Verify ND options properly + */ + +/* Set to 3 to get tracing... */ +#define ND_DEBUG 1 + +#define ND_PRINTK(fmt, args...) do { if (net_ratelimit()) { printk(fmt, ## args); } } while(0) +#define ND_NOPRINTK(x...) do { ; } while(0) +#define ND_PRINTK0 ND_PRINTK +#define ND_PRINTK1 ND_NOPRINTK +#define ND_PRINTK2 ND_NOPRINTK +#define ND_PRINTK3 ND_NOPRINTK +#if ND_DEBUG >= 1 +#undef ND_PRINTK1 +#define ND_PRINTK1 ND_PRINTK +#endif +#if ND_DEBUG >= 2 +#undef ND_PRINTK2 +#define ND_PRINTK2 ND_PRINTK +#endif +#if ND_DEBUG >= 3 +#undef ND_PRINTK3 +#define ND_PRINTK3 ND_PRINTK +#endif + +#include <linux/module.h> +#include <linux/errno.h> +#include <linux/types.h> +#include <linux/socket.h> +#include <linux/sockios.h> +#include <linux/sched.h> +#include <linux/net.h> +#include <linux/in6.h> +#include <linux/route.h> +#include <linux/init.h> +#include <linux/rcupdate.h> +#include <linux/slab.h> +#ifdef CONFIG_SYSCTL +#include <linux/sysctl.h> +#endif + +#include <linux/if_addr.h> +#include <linux/if_arp.h> +#include <linux/ipv6.h> +#include <linux/icmpv6.h> +#include <linux/jhash.h> + +#include <net/sock.h> +#include <net/snmp.h> + +#include <net/ipv6.h> +#include <net/protocol.h> +#include <net/ndisc.h> +#include <net/ip6_route.h> +#include <net/addrconf.h> +#include <net/icmp.h> + +#include <net/netlink.h> +#include <linux/rtnetlink.h> + +#include <net/flow.h> +#include <net/ip6_checksum.h> +#include <net/inet_common.h> +#include <linux/proc_fs.h> + +#include <linux/netfilter.h> +#include <linux/netfilter_ipv6.h> + +static u32 ndisc_hash(const void *pkey, + const struct net_device *dev, + __u32 *hash_rnd); +static int ndisc_constructor(struct neighbour *neigh); +static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb); +static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb); +static int pndisc_constructor(struct pneigh_entry *n); +static void pndisc_destructor(struct pneigh_entry *n); +static void pndisc_redo(struct sk_buff *skb); + +static const struct neigh_ops ndisc_generic_ops = { + .family = AF_INET6, + .solicit = ndisc_solicit, + .error_report = ndisc_error_report, + .output = neigh_resolve_output, + .connected_output = neigh_connected_output, +}; + +static const struct neigh_ops ndisc_hh_ops = { + .family = AF_INET6, + .solicit = ndisc_solicit, + .error_report = ndisc_error_report, + .output = neigh_resolve_output, + .connected_output = neigh_resolve_output, +}; + + +static const struct neigh_ops ndisc_direct_ops = { + .family = AF_INET6, + .output = neigh_direct_output, + .connected_output = neigh_direct_output, +}; + +struct neigh_table nd_tbl = { + .family = AF_INET6, + .key_len = sizeof(struct in6_addr), + .hash = ndisc_hash, + .constructor = ndisc_constructor, + .pconstructor = pndisc_constructor, + .pdestructor = pndisc_destructor, + .proxy_redo = pndisc_redo, + .id = "ndisc_cache", + .parms = { + .tbl = &nd_tbl, + .base_reachable_time = ND_REACHABLE_TIME, + .retrans_time = ND_RETRANS_TIMER, + .gc_staletime = 60 * HZ, + .reachable_time = ND_REACHABLE_TIME, + .delay_probe_time = 5 * HZ, + .queue_len_bytes = 64*1024, + .ucast_probes = 3, + .mcast_probes = 3, + .anycast_delay = 1 * HZ, + .proxy_delay = (8 * HZ) / 10, + .proxy_qlen = 64, + }, + .gc_interval = 30 * HZ, + .gc_thresh1 = 128, + .gc_thresh2 = 512, + .gc_thresh3 = 1024, +}; + +/* ND options */ +struct ndisc_options { + struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX]; +#ifdef CONFIG_IPV6_ROUTE_INFO + struct nd_opt_hdr *nd_opts_ri; + struct nd_opt_hdr *nd_opts_ri_end; +#endif + struct nd_opt_hdr *nd_useropts; + struct nd_opt_hdr *nd_useropts_end; +}; + +#define nd_opts_src_lladdr nd_opt_array[ND_OPT_SOURCE_LL_ADDR] +#define nd_opts_tgt_lladdr nd_opt_array[ND_OPT_TARGET_LL_ADDR] +#define nd_opts_pi nd_opt_array[ND_OPT_PREFIX_INFO] +#define nd_opts_pi_end nd_opt_array[__ND_OPT_PREFIX_INFO_END] +#define nd_opts_rh nd_opt_array[ND_OPT_REDIRECT_HDR] +#define nd_opts_mtu nd_opt_array[ND_OPT_MTU] + +#define NDISC_OPT_SPACE(len) (((len)+2+7)&~7) + +/* + * Return the padding between the option length and the start of the + * link addr. Currently only IP-over-InfiniBand needs this, although + * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may + * also need a pad of 2. + */ +static int ndisc_addr_option_pad(unsigned short type) +{ + switch (type) { + case ARPHRD_INFINIBAND: return 2; + default: return 0; + } +} + +static inline int ndisc_opt_addr_space(struct net_device *dev) +{ + return NDISC_OPT_SPACE(dev->addr_len + ndisc_addr_option_pad(dev->type)); +} + +static u8 *ndisc_fill_addr_option(u8 *opt, int type, void *data, int data_len, + unsigned short addr_type) +{ + int space = NDISC_OPT_SPACE(data_len); + int pad = ndisc_addr_option_pad(addr_type); + + opt[0] = type; + opt[1] = space>>3; + + memset(opt + 2, 0, pad); + opt += pad; + space -= pad; + + memcpy(opt+2, data, data_len); + data_len += 2; + opt += data_len; + if ((space -= data_len) > 0) + memset(opt, 0, space); + return opt + space; +} + +static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur, + struct nd_opt_hdr *end) +{ + int type; + if (!cur || !end || cur >= end) + return NULL; + type = cur->nd_opt_type; + do { + cur = ((void *)cur) + (cur->nd_opt_len << 3); + } while(cur < end && cur->nd_opt_type != type); + return cur <= end && cur->nd_opt_type == type ? cur : NULL; +} + +static inline int ndisc_is_useropt(struct nd_opt_hdr *opt) +{ + return opt->nd_opt_type == ND_OPT_RDNSS; +} + +static struct nd_opt_hdr *ndisc_next_useropt(struct nd_opt_hdr *cur, + struct nd_opt_hdr *end) +{ + if (!cur || !end || cur >= end) + return NULL; + do { + cur = ((void *)cur) + (cur->nd_opt_len << 3); + } while(cur < end && !ndisc_is_useropt(cur)); + return cur <= end && ndisc_is_useropt(cur) ? cur : NULL; +} + +static struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len, + struct ndisc_options *ndopts) +{ + struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt; + + if (!nd_opt || opt_len < 0 || !ndopts) + return NULL; + memset(ndopts, 0, sizeof(*ndopts)); + while (opt_len) { + int l; + if (opt_len < sizeof(struct nd_opt_hdr)) + return NULL; + l = nd_opt->nd_opt_len << 3; + if (opt_len < l || l == 0) + return NULL; + switch (nd_opt->nd_opt_type) { + case ND_OPT_SOURCE_LL_ADDR: + case ND_OPT_TARGET_LL_ADDR: + case ND_OPT_MTU: + case ND_OPT_REDIRECT_HDR: + if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) { + ND_PRINTK2(KERN_WARNING + "%s(): duplicated ND6 option found: type=%d\n", + __func__, + nd_opt->nd_opt_type); + } else { + ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; + } + break; + case ND_OPT_PREFIX_INFO: + ndopts->nd_opts_pi_end = nd_opt; + if (!ndopts->nd_opt_array[nd_opt->nd_opt_type]) + ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; + break; +#ifdef CONFIG_IPV6_ROUTE_INFO + case ND_OPT_ROUTE_INFO: + ndopts->nd_opts_ri_end = nd_opt; + if (!ndopts->nd_opts_ri) + ndopts->nd_opts_ri = nd_opt; + break; +#endif + default: + if (ndisc_is_useropt(nd_opt)) { + ndopts->nd_useropts_end = nd_opt; + if (!ndopts->nd_useropts) + ndopts->nd_useropts = nd_opt; + } else { + /* + * Unknown options must be silently ignored, + * to accommodate future extension to the + * protocol. + */ + ND_PRINTK2(KERN_NOTICE + "%s(): ignored unsupported option; type=%d, len=%d\n", + __func__, + nd_opt->nd_opt_type, nd_opt->nd_opt_len); + } + } + opt_len -= l; + nd_opt = ((void *)nd_opt) + l; + } + return ndopts; +} + +static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p, + struct net_device *dev) +{ + u8 *lladdr = (u8 *)(p + 1); + int lladdrlen = p->nd_opt_len << 3; + int prepad = ndisc_addr_option_pad(dev->type); + if (lladdrlen != NDISC_OPT_SPACE(dev->addr_len + prepad)) + return NULL; + return lladdr + prepad; +} + +int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir) +{ + switch (dev->type) { + case ARPHRD_ETHER: + case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */ + case ARPHRD_FDDI: + ipv6_eth_mc_map(addr, buf); + return 0; + case ARPHRD_IEEE802_TR: + ipv6_tr_mc_map(addr,buf); + return 0; + case ARPHRD_ARCNET: + ipv6_arcnet_mc_map(addr, buf); + return 0; + case ARPHRD_INFINIBAND: + ipv6_ib_mc_map(addr, dev->broadcast, buf); + return 0; + case ARPHRD_IPGRE: + return ipv6_ipgre_mc_map(addr, dev->broadcast, buf); + default: + if (dir) { + memcpy(buf, dev->broadcast, dev->addr_len); + return 0; + } + } + return -EINVAL; +} + +EXPORT_SYMBOL(ndisc_mc_map); + +static u32 ndisc_hash(const void *pkey, + const struct net_device *dev, + __u32 *hash_rnd) +{ + return ndisc_hashfn(pkey, dev, hash_rnd); +} + +static int ndisc_constructor(struct neighbour *neigh) +{ + struct in6_addr *addr = (struct in6_addr*)&neigh->primary_key; + struct net_device *dev = neigh->dev; + struct inet6_dev *in6_dev; + struct neigh_parms *parms; + int is_multicast = ipv6_addr_is_multicast(addr); + + in6_dev = in6_dev_get(dev); + if (in6_dev == NULL) { + return -EINVAL; + } + + parms = in6_dev->nd_parms; + __neigh_parms_put(neigh->parms); + neigh->parms = neigh_parms_clone(parms); + + neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST; + if (!dev->header_ops) { + neigh->nud_state = NUD_NOARP; + neigh->ops = &ndisc_direct_ops; + neigh->output = neigh_direct_output; + } else { + if (is_multicast) { + neigh->nud_state = NUD_NOARP; + ndisc_mc_map(addr, neigh->ha, dev, 1); + } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) { + neigh->nud_state = NUD_NOARP; + memcpy(neigh->ha, dev->dev_addr, dev->addr_len); + if (dev->flags&IFF_LOOPBACK) + neigh->type = RTN_LOCAL; + } else if (dev->flags&IFF_POINTOPOINT) { + neigh->nud_state = NUD_NOARP; + memcpy(neigh->ha, dev->broadcast, dev->addr_len); + } + if (dev->header_ops->cache) + neigh->ops = &ndisc_hh_ops; + else + neigh->ops = &ndisc_generic_ops; + if (neigh->nud_state&NUD_VALID) + neigh->output = neigh->ops->connected_output; + else + neigh->output = neigh->ops->output; + } + in6_dev_put(in6_dev); + return 0; +} + +static int pndisc_constructor(struct pneigh_entry *n) +{ + struct in6_addr *addr = (struct in6_addr*)&n->key; + struct in6_addr maddr; + struct net_device *dev = n->dev; + + if (dev == NULL || __in6_dev_get(dev) == NULL) + return -EINVAL; + addrconf_addr_solict_mult(addr, &maddr); + ipv6_dev_mc_inc(dev, &maddr); + return 0; +} + +static void pndisc_destructor(struct pneigh_entry *n) +{ + struct in6_addr *addr = (struct in6_addr*)&n->key; + struct in6_addr maddr; + struct net_device *dev = n->dev; + + if (dev == NULL || __in6_dev_get(dev) == NULL) + return; + addrconf_addr_solict_mult(addr, &maddr); + ipv6_dev_mc_dec(dev, &maddr); +} + +struct sk_buff *ndisc_build_skb(struct net_device *dev, + const struct in6_addr *daddr, + const struct in6_addr *saddr, + struct icmp6hdr *icmp6h, + const struct in6_addr *target, + int llinfo) +{ + struct net *net = dev_net(dev); + struct sock *sk = net->ipv6.ndisc_sk; + struct sk_buff *skb; + struct icmp6hdr *hdr; + int hlen = LL_RESERVED_SPACE(dev); + int tlen = dev->needed_tailroom; + int len; + int err; + u8 *opt; + + if (!dev->addr_len) + llinfo = 0; + + len = sizeof(struct icmp6hdr) + (target ? sizeof(*target) : 0); + if (llinfo) + len += ndisc_opt_addr_space(dev); + + skb = sock_alloc_send_skb(sk, + (MAX_HEADER + sizeof(struct ipv6hdr) + + len + hlen + tlen), + 1, &err); + if (!skb) { + ND_PRINTK0(KERN_ERR + "ICMPv6 ND: %s() failed to allocate an skb, err=%d.\n", + __func__, err); + return NULL; + } + + skb_reserve(skb, hlen); + ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len); + + skb->transport_header = skb->tail; + skb_put(skb, len); + + hdr = (struct icmp6hdr *)skb_transport_header(skb); + memcpy(hdr, icmp6h, sizeof(*hdr)); + + opt = skb_transport_header(skb) + sizeof(struct icmp6hdr); + if (target) { + *(struct in6_addr *)opt = *target; + opt += sizeof(*target); + } + + if (llinfo) + ndisc_fill_addr_option(opt, llinfo, dev->dev_addr, + dev->addr_len, dev->type); + + hdr->icmp6_cksum = csum_ipv6_magic(saddr, daddr, len, + IPPROTO_ICMPV6, + csum_partial(hdr, + len, 0)); + + return skb; +} + +EXPORT_SYMBOL(ndisc_build_skb); + +void ndisc_send_skb(struct sk_buff *skb, + struct net_device *dev, + struct neighbour *neigh, + const struct in6_addr *daddr, + const struct in6_addr *saddr, + struct icmp6hdr *icmp6h) +{ + struct flowi6 fl6; + struct dst_entry *dst; + struct net *net = dev_net(dev); + struct sock *sk = net->ipv6.ndisc_sk; + struct inet6_dev *idev; + int err; + u8 type; + + type = icmp6h->icmp6_type; + + icmpv6_flow_init(sk, &fl6, type, saddr, daddr, dev->ifindex); + dst = icmp6_dst_alloc(dev, neigh, &fl6); + if (IS_ERR(dst)) { + kfree_skb(skb); + return; + } + + skb_dst_set(skb, dst); + + rcu_read_lock(); + idev = __in6_dev_get(dst->dev); + IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len); + + err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL, dst->dev, + dst_output); + if (!err) { + ICMP6MSGOUT_INC_STATS(net, idev, type); + ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); + } + + rcu_read_unlock(); +} + +EXPORT_SYMBOL(ndisc_send_skb); + +/* + * Send a Neighbour Discover packet + */ +static void __ndisc_send(struct net_device *dev, + struct neighbour *neigh, + const struct in6_addr *daddr, + const struct in6_addr *saddr, + struct icmp6hdr *icmp6h, const struct in6_addr *target, + int llinfo) +{ + struct sk_buff *skb; + + skb = ndisc_build_skb(dev, daddr, saddr, icmp6h, target, llinfo); + if (!skb) + return; + + ndisc_send_skb(skb, dev, neigh, daddr, saddr, icmp6h); +} + +static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh, + const struct in6_addr *daddr, + const struct in6_addr *solicited_addr, + int router, int solicited, int override, int inc_opt) +{ + struct in6_addr tmpaddr; + struct inet6_ifaddr *ifp; + const struct in6_addr *src_addr; + struct icmp6hdr icmp6h = { + .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT, + }; + + /* for anycast or proxy, solicited_addr != src_addr */ + ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1); + if (ifp) { + src_addr = solicited_addr; + if (ifp->flags & IFA_F_OPTIMISTIC) + override = 0; + inc_opt |= ifp->idev->cnf.force_tllao; + in6_ifa_put(ifp); + } else { + if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr, + inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs, + &tmpaddr)) + return; + src_addr = &tmpaddr; + } + + icmp6h.icmp6_router = router; + icmp6h.icmp6_solicited = solicited; + icmp6h.icmp6_override = override; + + __ndisc_send(dev, neigh, daddr, src_addr, + &icmp6h, solicited_addr, + inc_opt ? ND_OPT_TARGET_LL_ADDR : 0); +} + +static void ndisc_send_unsol_na(struct net_device *dev) +{ + struct inet6_dev *idev; + struct inet6_ifaddr *ifa; + struct in6_addr mcaddr; + + idev = in6_dev_get(dev); + if (!idev) + return; + + read_lock_bh(&idev->lock); + list_for_each_entry(ifa, &idev->addr_list, if_list) { + addrconf_addr_solict_mult(&ifa->addr, &mcaddr); + ndisc_send_na(dev, NULL, &mcaddr, &ifa->addr, + /*router=*/ !!idev->cnf.forwarding, + /*solicited=*/ false, /*override=*/ true, + /*inc_opt=*/ true); + } + read_unlock_bh(&idev->lock); + + in6_dev_put(idev); +} + +void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh, + const struct in6_addr *solicit, + const struct in6_addr *daddr, const struct in6_addr *saddr) +{ + struct in6_addr addr_buf; + struct icmp6hdr icmp6h = { + .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION, + }; + + if (saddr == NULL) { + if (ipv6_get_lladdr(dev, &addr_buf, + (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))) + return; + saddr = &addr_buf; + } + + __ndisc_send(dev, neigh, daddr, saddr, + &icmp6h, solicit, + !ipv6_addr_any(saddr) ? ND_OPT_SOURCE_LL_ADDR : 0); +} + +void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr, + const struct in6_addr *daddr) +{ + struct icmp6hdr icmp6h = { + .icmp6_type = NDISC_ROUTER_SOLICITATION, + }; + int send_sllao = dev->addr_len; + +#ifdef CONFIG_IPV6_OPTIMISTIC_DAD + /* + * According to section 2.2 of RFC 4429, we must not + * send router solicitations with a sllao from + * optimistic addresses, but we may send the solicitation + * if we don't include the sllao. So here we check + * if our address is optimistic, and if so, we + * suppress the inclusion of the sllao. + */ + if (send_sllao) { + struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr, + dev, 1); + if (ifp) { + if (ifp->flags & IFA_F_OPTIMISTIC) { + send_sllao = 0; + } + in6_ifa_put(ifp); + } else { + send_sllao = 0; + } + } +#endif + __ndisc_send(dev, NULL, daddr, saddr, + &icmp6h, NULL, + send_sllao ? ND_OPT_SOURCE_LL_ADDR : 0); +} + + +static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb) +{ + /* + * "The sender MUST return an ICMP + * destination unreachable" + */ + dst_link_failure(skb); + kfree_skb(skb); +} + +/* Called with locked neigh: either read or both */ + +static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb) +{ + struct in6_addr *saddr = NULL; + struct in6_addr mcaddr; + struct net_device *dev = neigh->dev; + struct in6_addr *target = (struct in6_addr *)&neigh->primary_key; + int probes = atomic_read(&neigh->probes); + + if (skb && ipv6_chk_addr(dev_net(dev), &ipv6_hdr(skb)->saddr, dev, 1)) + saddr = &ipv6_hdr(skb)->saddr; + + if ((probes -= neigh->parms->ucast_probes) < 0) { + if (!(neigh->nud_state & NUD_VALID)) { + ND_PRINTK1(KERN_DEBUG "%s(): trying to ucast probe in NUD_INVALID: %pI6\n", + __func__, target); + } + ndisc_send_ns(dev, neigh, target, target, saddr); + } else if ((probes -= neigh->parms->app_probes) < 0) { +#ifdef CONFIG_ARPD + neigh_app_ns(neigh); +#endif + } else { + addrconf_addr_solict_mult(target, &mcaddr); + ndisc_send_ns(dev, NULL, target, &mcaddr, saddr); + } +} + +static int pndisc_is_router(const void *pkey, + struct net_device *dev) +{ + struct pneigh_entry *n; + int ret = -1; + + read_lock_bh(&nd_tbl.lock); + n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev); + if (n) + ret = !!(n->flags & NTF_ROUTER); + read_unlock_bh(&nd_tbl.lock); + + return ret; +} + +static void ndisc_recv_ns(struct sk_buff *skb) +{ + struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); + const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; + const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; + u8 *lladdr = NULL; + u32 ndoptlen = skb->tail - (skb->transport_header + + offsetof(struct nd_msg, opt)); + struct ndisc_options ndopts; + struct net_device *dev = skb->dev; + struct inet6_ifaddr *ifp; + struct inet6_dev *idev = NULL; + struct neighbour *neigh; + int dad = ipv6_addr_any(saddr); + int inc; + int is_router = -1; + + if (ipv6_addr_is_multicast(&msg->target)) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 NS: multicast target address"); + return; + } + + /* + * RFC2461 7.1.1: + * DAD has to be destined for solicited node multicast address. + */ + if (dad && + !(daddr->s6_addr32[0] == htonl(0xff020000) && + daddr->s6_addr32[1] == htonl(0x00000000) && + daddr->s6_addr32[2] == htonl(0x00000001) && + daddr->s6_addr [12] == 0xff )) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 NS: bad DAD packet (wrong destination)\n"); + return; + } + + if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 NS: invalid ND options\n"); + return; + } + + if (ndopts.nd_opts_src_lladdr) { + lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev); + if (!lladdr) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 NS: invalid link-layer address length\n"); + return; + } + + /* RFC2461 7.1.1: + * If the IP source address is the unspecified address, + * there MUST NOT be source link-layer address option + * in the message. + */ + if (dad) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 NS: bad DAD packet (link-layer address option)\n"); + return; + } + } + + inc = ipv6_addr_is_multicast(daddr); + + ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1); + if (ifp) { + + if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) { + if (dad) { + if (dev->type == ARPHRD_IEEE802_TR) { + const unsigned char *sadr; + sadr = skb_mac_header(skb); + if (((sadr[8] ^ dev->dev_addr[0]) & 0x7f) == 0 && + sadr[9] == dev->dev_addr[1] && + sadr[10] == dev->dev_addr[2] && + sadr[11] == dev->dev_addr[3] && + sadr[12] == dev->dev_addr[4] && + sadr[13] == dev->dev_addr[5]) { + /* looped-back to us */ + goto out; + } + } + + /* + * We are colliding with another node + * who is doing DAD + * so fail our DAD process + */ + addrconf_dad_failure(ifp); + return; + } else { + /* + * This is not a dad solicitation. + * If we are an optimistic node, + * we should respond. + * Otherwise, we should ignore it. + */ + if (!(ifp->flags & IFA_F_OPTIMISTIC)) + goto out; + } + } + + idev = ifp->idev; + } else { + struct net *net = dev_net(dev); + + idev = in6_dev_get(dev); + if (!idev) { + /* XXX: count this drop? */ + return; + } + + if (ipv6_chk_acast_addr(net, dev, &msg->target) || + (idev->cnf.forwarding && + (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) && + (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) { + if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) && + skb->pkt_type != PACKET_HOST && + inc != 0 && + idev->nd_parms->proxy_delay != 0) { + /* + * for anycast or proxy, + * sender should delay its response + * by a random time between 0 and + * MAX_ANYCAST_DELAY_TIME seconds. + * (RFC2461) -- yoshfuji + */ + struct sk_buff *n = skb_clone(skb, GFP_ATOMIC); + if (n) + pneigh_enqueue(&nd_tbl, idev->nd_parms, n); + goto out; + } + } else + goto out; + } + + if (is_router < 0) + is_router = !!idev->cnf.forwarding; + + if (dad) { + ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &msg->target, + is_router, 0, (ifp != NULL), 1); + goto out; + } + + if (inc) + NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast); + else + NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast); + + /* + * update / create cache entry + * for the source address + */ + neigh = __neigh_lookup(&nd_tbl, saddr, dev, + !inc || lladdr || !dev->addr_len); + if (neigh) + neigh_update(neigh, lladdr, NUD_STALE, + NEIGH_UPDATE_F_WEAK_OVERRIDE| + NEIGH_UPDATE_F_OVERRIDE); + if (neigh || !dev->header_ops) { + ndisc_send_na(dev, neigh, saddr, &msg->target, + is_router, + 1, (ifp != NULL && inc), inc); + if (neigh) + neigh_release(neigh); + } + +out: + if (ifp) + in6_ifa_put(ifp); + else + in6_dev_put(idev); +} + +static void ndisc_recv_na(struct sk_buff *skb) +{ + struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); + const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; + const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; + u8 *lladdr = NULL; + u32 ndoptlen = skb->tail - (skb->transport_header + + offsetof(struct nd_msg, opt)); + struct ndisc_options ndopts; + struct net_device *dev = skb->dev; + struct inet6_ifaddr *ifp; + struct neighbour *neigh; + + if (skb->len < sizeof(struct nd_msg)) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 NA: packet too short\n"); + return; + } + + if (ipv6_addr_is_multicast(&msg->target)) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 NA: target address is multicast.\n"); + return; + } + + if (ipv6_addr_is_multicast(daddr) && + msg->icmph.icmp6_solicited) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 NA: solicited NA is multicasted.\n"); + return; + } + + if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 NS: invalid ND option\n"); + return; + } + if (ndopts.nd_opts_tgt_lladdr) { + lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev); + if (!lladdr) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 NA: invalid link-layer address length\n"); + return; + } + } + ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1); + if (ifp) { + if (skb->pkt_type != PACKET_LOOPBACK + && (ifp->flags & IFA_F_TENTATIVE)) { + addrconf_dad_failure(ifp); + return; + } + /* What should we make now? The advertisement + is invalid, but ndisc specs say nothing + about it. It could be misconfiguration, or + an smart proxy agent tries to help us :-) + + We should not print the error if NA has been + received from loopback - it is just our own + unsolicited advertisement. + */ + if (skb->pkt_type != PACKET_LOOPBACK) + ND_PRINTK1(KERN_WARNING + "ICMPv6 NA: someone advertises our address %pI6 on %s!\n", + &ifp->addr, ifp->idev->dev->name); + in6_ifa_put(ifp); + return; + } + neigh = neigh_lookup(&nd_tbl, &msg->target, dev); + + if (neigh) { + u8 old_flags = neigh->flags; + struct net *net = dev_net(dev); + + if (neigh->nud_state & NUD_FAILED) + goto out; + + /* + * Don't update the neighbor cache entry on a proxy NA from + * ourselves because either the proxied node is off link or it + * has already sent a NA to us. + */ + if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) && + net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp && + pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) { + /* XXX: idev->cnf.prixy_ndp */ + goto out; + } + + neigh_update(neigh, lladdr, + msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE, + NEIGH_UPDATE_F_WEAK_OVERRIDE| + (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)| + NEIGH_UPDATE_F_OVERRIDE_ISROUTER| + (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0)); + + if ((old_flags & ~neigh->flags) & NTF_ROUTER) { + /* + * Change: router to host + */ + struct rt6_info *rt; + rt = rt6_get_dflt_router(saddr, dev); + if (rt) + ip6_del_rt(rt); + } + +out: + neigh_release(neigh); + } +} + +static void ndisc_recv_rs(struct sk_buff *skb) +{ + struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb); + unsigned long ndoptlen = skb->len - sizeof(*rs_msg); + struct neighbour *neigh; + struct inet6_dev *idev; + const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; + struct ndisc_options ndopts; + u8 *lladdr = NULL; + + if (skb->len < sizeof(*rs_msg)) + return; + + idev = __in6_dev_get(skb->dev); + if (!idev) { + if (net_ratelimit()) + ND_PRINTK1("ICMP6 RS: can't find in6 device\n"); + return; + } + + /* Don't accept RS if we're not in router mode */ + if (!idev->cnf.forwarding) + goto out; + + /* + * Don't update NCE if src = ::; + * this implies that the source node has no ip address assigned yet. + */ + if (ipv6_addr_any(saddr)) + goto out; + + /* Parse ND options */ + if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) { + if (net_ratelimit()) + ND_PRINTK2("ICMP6 NS: invalid ND option, ignored\n"); + goto out; + } + + if (ndopts.nd_opts_src_lladdr) { + lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, + skb->dev); + if (!lladdr) + goto out; + } + + neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1); + if (neigh) { + neigh_update(neigh, lladdr, NUD_STALE, + NEIGH_UPDATE_F_WEAK_OVERRIDE| + NEIGH_UPDATE_F_OVERRIDE| + NEIGH_UPDATE_F_OVERRIDE_ISROUTER); + neigh_release(neigh); + } +out: + return; +} + +static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt) +{ + struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra); + struct sk_buff *skb; + struct nlmsghdr *nlh; + struct nduseroptmsg *ndmsg; + struct net *net = dev_net(ra->dev); + int err; + int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg) + + (opt->nd_opt_len << 3)); + size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr)); + + skb = nlmsg_new(msg_size, GFP_ATOMIC); + if (skb == NULL) { + err = -ENOBUFS; + goto errout; + } + + nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0); + if (nlh == NULL) { + goto nla_put_failure; + } + + ndmsg = nlmsg_data(nlh); + ndmsg->nduseropt_family = AF_INET6; + ndmsg->nduseropt_ifindex = ra->dev->ifindex; + ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type; + ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code; + ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3; + + memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3); + + NLA_PUT(skb, NDUSEROPT_SRCADDR, sizeof(struct in6_addr), + &ipv6_hdr(ra)->saddr); + nlmsg_end(skb, nlh); + + rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC); + return; + +nla_put_failure: + nlmsg_free(skb); + err = -EMSGSIZE; +errout: + rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err); +} + +static inline int accept_ra(struct inet6_dev *in6_dev) +{ + /* + * If forwarding is enabled, RA are not accepted unless the special + * hybrid mode (accept_ra=2) is enabled. + */ + if (in6_dev->cnf.forwarding && in6_dev->cnf.accept_ra < 2) + return 0; + + return in6_dev->cnf.accept_ra; +} + +static void ndisc_router_discovery(struct sk_buff *skb) +{ + struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb); + struct neighbour *neigh = NULL; + struct inet6_dev *in6_dev; + struct rt6_info *rt = NULL; + int lifetime; + struct ndisc_options ndopts; + int optlen; + unsigned int pref = 0; + + __u8 * opt = (__u8 *)(ra_msg + 1); + + optlen = (skb->tail - skb->transport_header) - sizeof(struct ra_msg); + + if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 RA: source address is not link-local.\n"); + return; + } + if (optlen < 0) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 RA: packet too short\n"); + return; + } + +#ifdef CONFIG_IPV6_NDISC_NODETYPE + if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 RA: from host or unauthorized router\n"); + return; + } +#endif + + /* + * set the RA_RECV flag in the interface + */ + + in6_dev = __in6_dev_get(skb->dev); + if (in6_dev == NULL) { + ND_PRINTK0(KERN_ERR + "ICMPv6 RA: can't find inet6 device for %s.\n", + skb->dev->name); + return; + } + + if (!ndisc_parse_options(opt, optlen, &ndopts)) { + ND_PRINTK2(KERN_WARNING + "ICMP6 RA: invalid ND options\n"); + return; + } + + if (!accept_ra(in6_dev)) + goto skip_linkparms; + +#ifdef CONFIG_IPV6_NDISC_NODETYPE + /* skip link-specific parameters from interior routers */ + if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) + goto skip_linkparms; +#endif + + if (in6_dev->if_flags & IF_RS_SENT) { + /* + * flag that an RA was received after an RS was sent + * out on this interface. + */ + in6_dev->if_flags |= IF_RA_RCVD; + } + + /* + * Remember the managed/otherconf flags from most recently + * received RA message (RFC 2462) -- yoshfuji + */ + in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED | + IF_RA_OTHERCONF)) | + (ra_msg->icmph.icmp6_addrconf_managed ? + IF_RA_MANAGED : 0) | + (ra_msg->icmph.icmp6_addrconf_other ? + IF_RA_OTHERCONF : 0); + + if (!in6_dev->cnf.accept_ra_defrtr) + goto skip_defrtr; + + if (ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, NULL, 0)) + goto skip_defrtr; + + lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime); + +#ifdef CONFIG_IPV6_ROUTER_PREF + pref = ra_msg->icmph.icmp6_router_pref; + /* 10b is handled as if it were 00b (medium) */ + if (pref == ICMPV6_ROUTER_PREF_INVALID || + !in6_dev->cnf.accept_ra_rtr_pref) + pref = ICMPV6_ROUTER_PREF_MEDIUM; +#endif + + rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev); + + if (rt) { + neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr); + if (!neigh) { + ND_PRINTK0(KERN_ERR + "ICMPv6 RA: %s() got default router without neighbour.\n", + __func__); + dst_release(&rt->dst); + return; + } + } + if (rt && lifetime == 0) { + ip6_del_rt(rt); + rt = NULL; + } + + if (rt == NULL && lifetime) { + ND_PRINTK3(KERN_DEBUG + "ICMPv6 RA: adding default router.\n"); + + rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref); + if (rt == NULL) { + ND_PRINTK0(KERN_ERR + "ICMPv6 RA: %s() failed to add default route.\n", + __func__); + return; + } + + neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr); + if (neigh == NULL) { + ND_PRINTK0(KERN_ERR + "ICMPv6 RA: %s() got default router without neighbour.\n", + __func__); + dst_release(&rt->dst); + return; + } + neigh->flags |= NTF_ROUTER; + } else if (rt) { + rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref); + } + + if (rt) + rt6_set_expires(rt, jiffies + (HZ * lifetime)); + if (ra_msg->icmph.icmp6_hop_limit) { + in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit; + if (rt) + dst_metric_set(&rt->dst, RTAX_HOPLIMIT, + ra_msg->icmph.icmp6_hop_limit); + } + +skip_defrtr: + + /* + * Update Reachable Time and Retrans Timer + */ + + if (in6_dev->nd_parms) { + unsigned long rtime = ntohl(ra_msg->retrans_timer); + + if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) { + rtime = (rtime*HZ)/1000; + if (rtime < HZ/10) + rtime = HZ/10; + in6_dev->nd_parms->retrans_time = rtime; + in6_dev->tstamp = jiffies; + inet6_ifinfo_notify(RTM_NEWLINK, in6_dev); + } + + rtime = ntohl(ra_msg->reachable_time); + if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) { + rtime = (rtime*HZ)/1000; + + if (rtime < HZ/10) + rtime = HZ/10; + + if (rtime != in6_dev->nd_parms->base_reachable_time) { + in6_dev->nd_parms->base_reachable_time = rtime; + in6_dev->nd_parms->gc_staletime = 3 * rtime; + in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime); + in6_dev->tstamp = jiffies; + inet6_ifinfo_notify(RTM_NEWLINK, in6_dev); + } + } + } + +skip_linkparms: + + /* + * Process options. + */ + + if (!neigh) + neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr, + skb->dev, 1); + if (neigh) { + u8 *lladdr = NULL; + if (ndopts.nd_opts_src_lladdr) { + lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, + skb->dev); + if (!lladdr) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 RA: invalid link-layer address length\n"); + goto out; + } + } + neigh_update(neigh, lladdr, NUD_STALE, + NEIGH_UPDATE_F_WEAK_OVERRIDE| + NEIGH_UPDATE_F_OVERRIDE| + NEIGH_UPDATE_F_OVERRIDE_ISROUTER| + NEIGH_UPDATE_F_ISROUTER); + } + + if (!accept_ra(in6_dev)) + goto out; + +#ifdef CONFIG_IPV6_ROUTE_INFO + if (ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, NULL, 0)) + goto skip_routeinfo; + + if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) { + struct nd_opt_hdr *p; + for (p = ndopts.nd_opts_ri; + p; + p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) { + struct route_info *ri = (struct route_info *)p; +#ifdef CONFIG_IPV6_NDISC_NODETYPE + if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT && + ri->prefix_len == 0) + continue; +#endif + if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen) + continue; + rt6_route_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3, + &ipv6_hdr(skb)->saddr); + } + } + +skip_routeinfo: +#endif + +#ifdef CONFIG_IPV6_NDISC_NODETYPE + /* skip link-specific ndopts from interior routers */ + if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) + goto out; +#endif + + if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) { + struct nd_opt_hdr *p; + for (p = ndopts.nd_opts_pi; + p; + p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) { + addrconf_prefix_rcv(skb->dev, (u8 *)p, + (p->nd_opt_len) << 3, + ndopts.nd_opts_src_lladdr != NULL); + } + } + + if (ndopts.nd_opts_mtu) { + __be32 n; + u32 mtu; + + memcpy(&n, ((u8*)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu)); + mtu = ntohl(n); + + if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 RA: invalid mtu: %d\n", + mtu); + } else if (in6_dev->cnf.mtu6 != mtu) { + in6_dev->cnf.mtu6 = mtu; + + if (rt) + dst_metric_set(&rt->dst, RTAX_MTU, mtu); + + rt6_mtu_change(skb->dev, mtu); + } + } + + if (ndopts.nd_useropts) { + struct nd_opt_hdr *p; + for (p = ndopts.nd_useropts; + p; + p = ndisc_next_useropt(p, ndopts.nd_useropts_end)) { + ndisc_ra_useropt(skb, p); + } + } + + if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 RA: invalid RA options"); + } +out: + if (rt) + dst_release(&rt->dst); + if (neigh) + neigh_release(neigh); +} + +static void ndisc_redirect_rcv(struct sk_buff *skb) +{ + struct inet6_dev *in6_dev; + struct icmp6hdr *icmph; + const struct in6_addr *dest; + const struct in6_addr *target; /* new first hop to destination */ + struct neighbour *neigh; + int on_link = 0; + struct ndisc_options ndopts; + int optlen; + u8 *lladdr = NULL; + +#ifdef CONFIG_IPV6_NDISC_NODETYPE + switch (skb->ndisc_nodetype) { + case NDISC_NODETYPE_HOST: + case NDISC_NODETYPE_NODEFAULT: + ND_PRINTK2(KERN_WARNING + "ICMPv6 Redirect: from host or unauthorized router\n"); + return; + } +#endif + + if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 Redirect: source address is not link-local.\n"); + return; + } + + optlen = skb->tail - skb->transport_header; + optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr); + + if (optlen < 0) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 Redirect: packet too short\n"); + return; + } + + icmph = icmp6_hdr(skb); + target = (const struct in6_addr *) (icmph + 1); + dest = target + 1; + + if (ipv6_addr_is_multicast(dest)) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 Redirect: destination address is multicast.\n"); + return; + } + + if (ipv6_addr_equal(dest, target)) { + on_link = 1; + } else if (ipv6_addr_type(target) != + (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 Redirect: target address is not link-local unicast.\n"); + return; + } + + in6_dev = __in6_dev_get(skb->dev); + if (!in6_dev) + return; + if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects) + return; + + /* RFC2461 8.1: + * The IP source address of the Redirect MUST be the same as the current + * first-hop router for the specified ICMP Destination Address. + */ + + if (!ndisc_parse_options((u8*)(dest + 1), optlen, &ndopts)) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 Redirect: invalid ND options\n"); + return; + } + if (ndopts.nd_opts_tgt_lladdr) { + lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, + skb->dev); + if (!lladdr) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 Redirect: invalid link-layer address length\n"); + return; + } + } + + neigh = __neigh_lookup(&nd_tbl, target, skb->dev, 1); + if (neigh) { + rt6_redirect(dest, &ipv6_hdr(skb)->daddr, + &ipv6_hdr(skb)->saddr, neigh, lladdr, + on_link); + neigh_release(neigh); + } +} + +void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target) +{ + struct net_device *dev = skb->dev; + struct net *net = dev_net(dev); + struct sock *sk = net->ipv6.ndisc_sk; + int len = sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr); + struct sk_buff *buff; + struct icmp6hdr *icmph; + struct in6_addr saddr_buf; + struct in6_addr *addrp; + struct rt6_info *rt; + struct dst_entry *dst; + struct inet6_dev *idev; + struct flowi6 fl6; + u8 *opt; + int hlen, tlen; + int rd_len; + int err; + u8 ha_buf[MAX_ADDR_LEN], *ha = NULL; + + if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 Redirect: no link-local address on %s\n", + dev->name); + return; + } + + if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) && + ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 Redirect: target address is not link-local unicast.\n"); + return; + } + + icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT, + &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex); + + dst = ip6_route_output(net, NULL, &fl6); + if (dst->error) { + dst_release(dst); + return; + } + dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0); + if (IS_ERR(dst)) + return; + + rt = (struct rt6_info *) dst; + + if (rt->rt6i_flags & RTF_GATEWAY) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 Redirect: destination is not a neighbour.\n"); + goto release; + } + if (!rt->rt6i_peer) + rt6_bind_peer(rt, 1); + if (!inet_peer_xrlim_allow(rt->rt6i_peer, 1*HZ)) + goto release; + + if (dev->addr_len) { + struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target); + if (!neigh) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 Redirect: no neigh for target address\n"); + goto release; + } + + read_lock_bh(&neigh->lock); + if (neigh->nud_state & NUD_VALID) { + memcpy(ha_buf, neigh->ha, dev->addr_len); + read_unlock_bh(&neigh->lock); + ha = ha_buf; + len += ndisc_opt_addr_space(dev); + } else + read_unlock_bh(&neigh->lock); + + neigh_release(neigh); + } + + rd_len = min_t(unsigned int, + IPV6_MIN_MTU-sizeof(struct ipv6hdr)-len, skb->len + 8); + rd_len &= ~0x7; + len += rd_len; + + hlen = LL_RESERVED_SPACE(dev); + tlen = dev->needed_tailroom; + buff = sock_alloc_send_skb(sk, + (MAX_HEADER + sizeof(struct ipv6hdr) + + len + hlen + tlen), + 1, &err); + if (buff == NULL) { + ND_PRINTK0(KERN_ERR + "ICMPv6 Redirect: %s() failed to allocate an skb, err=%d.\n", + __func__, err); + goto release; + } + + skb_reserve(buff, hlen); + ip6_nd_hdr(sk, buff, dev, &saddr_buf, &ipv6_hdr(skb)->saddr, + IPPROTO_ICMPV6, len); + + skb_set_transport_header(buff, skb_tail_pointer(buff) - buff->data); + skb_put(buff, len); + icmph = icmp6_hdr(buff); + + memset(icmph, 0, sizeof(struct icmp6hdr)); + icmph->icmp6_type = NDISC_REDIRECT; + + /* + * copy target and destination addresses + */ + + addrp = (struct in6_addr *)(icmph + 1); + *addrp = *target; + addrp++; + *addrp = ipv6_hdr(skb)->daddr; + + opt = (u8*) (addrp + 1); + + /* + * include target_address option + */ + + if (ha) + opt = ndisc_fill_addr_option(opt, ND_OPT_TARGET_LL_ADDR, ha, + dev->addr_len, dev->type); + + /* + * build redirect option and copy skb over to the new packet. + */ + + memset(opt, 0, 8); + *(opt++) = ND_OPT_REDIRECT_HDR; + *(opt++) = (rd_len >> 3); + opt += 6; + + memcpy(opt, ipv6_hdr(skb), rd_len - 8); + + icmph->icmp6_cksum = csum_ipv6_magic(&saddr_buf, &ipv6_hdr(skb)->saddr, + len, IPPROTO_ICMPV6, + csum_partial(icmph, len, 0)); + + skb_dst_set(buff, dst); + rcu_read_lock(); + idev = __in6_dev_get(dst->dev); + IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len); + err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, buff, NULL, dst->dev, + dst_output); + if (!err) { + ICMP6MSGOUT_INC_STATS(net, idev, NDISC_REDIRECT); + ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); + } + + rcu_read_unlock(); + return; + +release: + dst_release(dst); +} + +static void pndisc_redo(struct sk_buff *skb) +{ + ndisc_recv_ns(skb); + kfree_skb(skb); +} + +int ndisc_rcv(struct sk_buff *skb) +{ + struct nd_msg *msg; + + if (!pskb_may_pull(skb, skb->len)) + return 0; + + msg = (struct nd_msg *)skb_transport_header(skb); + + __skb_push(skb, skb->data - skb_transport_header(skb)); + + if (ipv6_hdr(skb)->hop_limit != 255) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 NDISC: invalid hop-limit: %d\n", + ipv6_hdr(skb)->hop_limit); + return 0; + } + + if (msg->icmph.icmp6_code != 0) { + ND_PRINTK2(KERN_WARNING + "ICMPv6 NDISC: invalid ICMPv6 code: %d\n", + msg->icmph.icmp6_code); + return 0; + } + + memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); + + switch (msg->icmph.icmp6_type) { + case NDISC_NEIGHBOUR_SOLICITATION: + ndisc_recv_ns(skb); + break; + + case NDISC_NEIGHBOUR_ADVERTISEMENT: + ndisc_recv_na(skb); + break; + + case NDISC_ROUTER_SOLICITATION: + ndisc_recv_rs(skb); + break; + + case NDISC_ROUTER_ADVERTISEMENT: + ndisc_router_discovery(skb); + break; + + case NDISC_REDIRECT: + ndisc_redirect_rcv(skb); + break; + } + + return 0; +} + +static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) +{ + struct net_device *dev = ptr; + struct net *net = dev_net(dev); + + switch (event) { + case NETDEV_CHANGEADDR: + neigh_changeaddr(&nd_tbl, dev); + fib6_run_gc(~0UL, net); + break; + case NETDEV_DOWN: + neigh_ifdown(&nd_tbl, dev); + fib6_run_gc(~0UL, net); + break; + case NETDEV_NOTIFY_PEERS: + ndisc_send_unsol_na(dev); + break; + default: + break; + } + + return NOTIFY_DONE; +} + +static struct notifier_block ndisc_netdev_notifier = { + .notifier_call = ndisc_netdev_event, +}; + +#ifdef CONFIG_SYSCTL +static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl, + const char *func, const char *dev_name) +{ + static char warncomm[TASK_COMM_LEN]; + static int warned; + if (strcmp(warncomm, current->comm) && warned < 5) { + strcpy(warncomm, current->comm); + printk(KERN_WARNING + "process `%s' is using deprecated sysctl (%s) " + "net.ipv6.neigh.%s.%s; " + "Use net.ipv6.neigh.%s.%s_ms " + "instead.\n", + warncomm, func, + dev_name, ctl->procname, + dev_name, ctl->procname); + warned++; + } +} + +int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos) +{ + struct net_device *dev = ctl->extra1; + struct inet6_dev *idev; + int ret; + + if ((strcmp(ctl->procname, "retrans_time") == 0) || + (strcmp(ctl->procname, "base_reachable_time") == 0)) + ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default"); + + if (strcmp(ctl->procname, "retrans_time") == 0) + ret = proc_dointvec(ctl, write, buffer, lenp, ppos); + + else if (strcmp(ctl->procname, "base_reachable_time") == 0) + ret = proc_dointvec_jiffies(ctl, write, + buffer, lenp, ppos); + + else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) || + (strcmp(ctl->procname, "base_reachable_time_ms") == 0)) + ret = proc_dointvec_ms_jiffies(ctl, write, + buffer, lenp, ppos); + else + ret = -1; + + if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) { + if (ctl->data == &idev->nd_parms->base_reachable_time) + idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time); + idev->tstamp = jiffies; + inet6_ifinfo_notify(RTM_NEWLINK, idev); + in6_dev_put(idev); + } + return ret; +} + + +#endif + +static int __net_init ndisc_net_init(struct net *net) +{ + struct ipv6_pinfo *np; + struct sock *sk; + int err; + + err = inet_ctl_sock_create(&sk, PF_INET6, + SOCK_RAW, IPPROTO_ICMPV6, net); + if (err < 0) { + ND_PRINTK0(KERN_ERR + "ICMPv6 NDISC: Failed to initialize the control socket (err %d).\n", + err); + return err; + } + + net->ipv6.ndisc_sk = sk; + + np = inet6_sk(sk); + np->hop_limit = 255; + /* Do not loopback ndisc messages */ + np->mc_loop = 0; + + return 0; +} + +static void __net_exit ndisc_net_exit(struct net *net) +{ + inet_ctl_sock_destroy(net->ipv6.ndisc_sk); +} + +static struct pernet_operations ndisc_net_ops = { + .init = ndisc_net_init, + .exit = ndisc_net_exit, +}; + +int __init ndisc_init(void) +{ + int err; + + err = register_pernet_subsys(&ndisc_net_ops); + if (err) + return err; + /* + * Initialize the neighbour table + */ + neigh_table_init(&nd_tbl); + +#ifdef CONFIG_SYSCTL + err = neigh_sysctl_register(NULL, &nd_tbl.parms, "ipv6", + &ndisc_ifinfo_sysctl_change); + if (err) + goto out_unregister_pernet; +#endif + err = register_netdevice_notifier(&ndisc_netdev_notifier); + if (err) + goto out_unregister_sysctl; +out: + return err; + +out_unregister_sysctl: +#ifdef CONFIG_SYSCTL + neigh_sysctl_unregister(&nd_tbl.parms); +out_unregister_pernet: +#endif + unregister_pernet_subsys(&ndisc_net_ops); + goto out; +} + +void ndisc_cleanup(void) +{ + unregister_netdevice_notifier(&ndisc_netdev_notifier); +#ifdef CONFIG_SYSCTL + neigh_sysctl_unregister(&nd_tbl.parms); +#endif + neigh_table_clear(&nd_tbl); + unregister_pernet_subsys(&ndisc_net_ops); +} |